A 20-year-old from the Southwest Alaska village of Chevak admitted to Alaska State Troopers that he killed Roxanne Smart last year, according to charging documents.
Troopers have charged Samuel Atchak in the murder of Smart, 19, whose family members have frequently posted to social media about their search for answers since her death last August.
Atchak was arrested in Chevak on Friday shortly before 1 p.m., troopers said in an online dispatch.
Troopers went to the village of 1,000 residents on Thursday to conduct follow-up investigation into Smart's death.
According to the charges, Atchak told troopers he put Smart in a "choke hold" until she lost consciousness, then removed her clothing and sexually assaulted her.
He initially denied killing Smart, but when troopers were arresting Atchak for rape and assault, "he stated he did stab and murder Roxanne Smart the night he sexually assaulted her," according to the charging documents.
Charges include first-degree murder, first-degree sexual assault and second-degree assault.
Atchak was taken to Yukon Kuskokwim Correctional Center in Bethel, where he is being held without bail. Online court records indicate he made an initial court appearance Saturday morning and was assigned a public defender.
Troopers said in last August they were investigating the death of Smart as a homicide. Her body was found outside the village health clinic in Chevak. When troopers found Smart, according to the charges, she had multiple stab wounds to her chest and neck.